SLVSBK1E September 2012 – May 2014 TPS65631
PRODUCTION DATA.
Figure 10 shows a typical application circuit suitable for supplying AMOLED displays in smartphone applications. The circuit is designed to operate from a single-cell Li-Ion battery and generates a positive output voltage VPOS of 4.6 V and a negative output voltage of –4 V. Both outputs are capable of supplying up to 300 mA of output current.
For this design example, use the following input parameters.
DESIGN PARAMETER | EXAMPLE |
---|---|
Input voltage range | 2.9 V to 4.5 V |
Output voltage | VPOS = 4.6V, VNEG = –4 V |
Switching frequency | 1.7 MHz |
In order to maximize performance, the TPS65631 has been optimized for use with a relatively narrow range of component values, and customers are strongly recommended to use the application circuit shown in Figure 10 with the components listed in Table 3 and Table 4.
The boost converter and inverting buck-boost converter have been optimized for use with 4.7 µH inductors, and it is recommended that this value be used in all applications. Customers using other values of inductor are strongly recommended to characterize circuit performance on a case-by-case basis.
PARAMETER | VALUE | MANUFACTURER | PART NUMBER |
---|---|---|---|
L1, L2 | 4.7 µH | Coilmaster | MMPP252012-4R7N |
Toko | 1239AS-H-4R7M | ||
ABCO | LPP252012-4R7N | ||
Coilcraft | XFL4020-4R7ML |
The recommended capacitor values are shown in Table 4. Applications using less than the recommended capacitance (e.g. to save PCB area) may experience increased voltage ripple. In general, the lower the output power, the lower the necessary capacitance.
PARAMETER | VALUE | MANUFACTURER | PART NUMBER |
---|---|---|---|
C1 | 2 × 10 µF | Murata | GRM21BR71A106KE51 |
C2 | 10 µF | Murata | GRM21BR71A106KE51 |
C3 | 2 × 10 µF | Murata | GRM21BR71A106KE51 |
C4 | 100 nF | Murata | GRM21BR71E104KA01 |